1. FIELD OF THE INVENTION
This invention relates to fresh air inlets for fireplaces.
2. REVIEW OF THE PRIOR ART
It has long been considered advantageous in many instances to provide built-in fireplaces with an external source of combustion air. With improved draft sealing of modern houses, the absence of such a source can give rise to a hazard since air drawn from a house by a fireplace can give rise to a negative pressure differential within the house which can interfere with the proper operation of other combustion apparatus such as furnaces. This has given rise to regulatory requirements in certain jurisdictions for the provision in new construction of fresh air inlets for fireplaces, which inlets have to comply with certain requirements, e.g. the air opening must face away from the grate and be provided with a screen. The screen minimizes the risk of cinders or coals falling into the opening, which could constitute a hazard if they block, burn or overheat the air ducting connected to the vent opening. Such ducting is typically of light gauge aluminum, and is unsuited to protecting surrounding structures from excessive temperatures.
Fresh air vents must usually be installed during construction of the fireplace, which is typically carried out by a bricklayer or stonemason. Typical vents are fabricated from light gauge galvanized steel similar to that used for central heating ducting. Their handling and connection to the associated air ducting requires skills different from those of the average bricklayer, as well as tools not found in the customary bricklayer's tool-kit. Even the finished installation will be subject to quite rough handling, being typically located in the floor of the hearth just in front of the grate.